Possible Definitions:
1. Song (n.) That which is sung or uttered with musical modulations of the voice, whether of a human being or of a bird, insect, etc.
2. Song (n.) A lyrical poem adapted to vocal music; a ballad.
3. Song (n.) More generally, any poetical strain; a poem.
4. Song (n.) Poetical composition; poetry; verse.
5. Song (n.) An object of derision; a laughingstock.
6. Song (n.) A trifle.